Electric push-in plug



Nov. 15, 1938. H D. GEYER 2,136,498

ELECTRIC iUSH' IN PLUG Filed Dec. 13, 195-3 HI ATTORNEYS Patented Nov. 15, 193% STA ran T OFFICE aliases anaemic roan-m ratio Harvey D. Geyer, Dayton, Uhio, aesignor to cmerai Motors Corporation, troit, Mich, a corporation of Delaware application December lid, 1935, serial No. 54,165

4 Claims. (Gil.

This invention relates to electric connector plugs which may be attached to the end of a flexible electric cord for connecting electric appliiii by the open cure method and then have the lndividual bodies cut to length afterward.

Further features are the simple and edicient methods of connecting the electric wires to the individual contact prongs before any of these parts are slipped to their final positions in the soft rubber main body, and thereafter slipping these connected. parts as a unit to their final positions where they are firmly anchored in place. I

Further objects and advantages of'the present inventlon'willbe apparent from the following description, reference being hadv to the accompanying drawing wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

Fig. 1 is a side elevation of the completely assembled connector plug. I

Fig. 2 is an end view of Fig. l.

Fig. 3 shows the electric cord passed thru the main rubber body and thereafter attached to the two contact prongs and ready to have the rubber body pushed into its final position.

Fig. 4 is a section taken on line 4'-4 of Fig. 2.

Fig.5 is a perspective view of one of the metal contact prongs.

Figs. 6, 7, 8 show a second form of this inventlon.

Fig. 6 is a side elevation of the' assembled plug.

Fig. '7 shows the electric cord already attached to the two, contact prongs and the rubber body partially pushed into place over the two contact prongs. I

' Fig.8 is a, face view of one 01. the contact prongs.

Similar reference characters refer to similar parts throughout.

. Referring to Figures 1 to 5, l0 designates the resilient rubber main body of the connector plug which may have any desired external shape but which is preferably 0! the same crow section thruout its length in order that it may be first made in long lengths and the individual bodies ill! out to suitable length therefrom. Body it has a central cord-receiving recess ll extending therethru and on each side of recess ii is a contact prong-receiving recess Elli which communicates thruout its entire length with recess Ill thru the relatively small slots it. -Thus it is seen that all the recesses in body it are also or the same cross section thruout the length of the body. it. This permits the uncured rubber blank from which body it is made to be extruded in long lengths with all the recesses therein and these long lengths to be then vulcanized by the open cure method which greatly reduces the costs of making these bodies over any method where indi-, vidual molds are required.

The two contact prongs it are each bent up from a metal strip, preferably hard brass which is approximately .025 of an inch in thickness, to the shape clearly shown in Fig. -5. Each contact prong M has its inner and El bent back at an acute angle to form a resilient or compressible foot which terminates in two sharp points 22 which preferably are spread apart slightly more than the width of the prong 20. A simple and convenient means for connecting the wires 23 or the flexible electric cable 24 to the rongs iii will now be described. The end of cable 2t is first passed thru the central hole II in the main body l0 and the insulation removed from. the ends of the two wires 23. Tosecurely connect each wire 23 to its contact prong 20, the wire is first passed thru a small hole 26 in the prong and then wrapped one or more turns around the resilient metal foot 2| which preferably has notches 26 therein to better retain the wire .inplace. The parts will then be as clearly shown in Fig. 3. The final step of assembling is simply pushing the main body ID to the right as shown in Fig. 3 with sufficient force so that each prong 20 will enter its recess l2 and the transverse portion of each wire 23 will slide along the communicating slots l3. As each resilient metal foot 2i enters its recess l2 it will be pressed tightly down upon the wire end 23 wrapped therearound and thus each wire is very firmly-anchored to its prong 20. The resiliency of the metal and the tight flt however causes the sharp metal points or spurs 22 to bite into the confining soft rubber body l0,

" substantially as illustrated in Fig. 4, thus firmly anchoring the contact prong 20 in place. Obviously the spurs 22 will serve as barbs to prevent the prongs 20 from being pulled out or therubber body I! in the reversedirection. It desired, the

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ends of wires 23 may be connected to the prongs 20 by any suitable means other than as above described, since when the parts are in the position shown in Fig. 3 ready access can be had for any desired type of connection.

Figs. 6, 7 and 8 show a slightly modified form of the invention. In this form the main body III of soft rubber or the likelis the same as that described above. In this second form the two metal contact prongs 30 are stamped from heavier metal, preferably from a brass strip about .05 of an inch thick and .25 of an inch wide. Each prong 30 has a small hole 3| to receive the end of a wire 23' after its insulation is removed. The projecting uninsulated end 32 of the wire 23 may then be easily soldered to the brass prong 30 as clearly" shown in Fig. '7. In order to facilitate this soldering operation at the time of assembling the connector plug, a small piece of solder wire 35 containing a resin or flux core may be tinned to one side of each prong 30 at the time it is made (as shown in Fig. 8). Hence at the time of assembling it will be necessary only to bend the wire end 32 down against the attached solder piece 35 and apply only a slight amount of heat as by a soldering iron.

The inner ends of the prongs 30 have laterally spread sharp *netal points 36 as shown in Fig. 8. Now when the prongs 30 are pushed with considerable force into their tight-fitting recesses I2 with the parts as illustrated in Fig. 7, the transverse portions of wires 23' will slide along the open slots [3 in body l and thus permit the end of cable 24' to be forced to a position substantially within the body Ill. The sharp metal spurs 36 bite into the confining rubber and thus aid in firmly anchoring the contact prongs 30 within the main body II). If desired, the soldering of the wire ends 32 to the prongs 30 may be omitted since the pressure of the rubber body l0 upon these ends 32 will prevent them from being pulled out of the small holes 3| in the prongs whether or not there is a'solder connection.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. An electric push-in plug attached to the end of a flexible electric cord, said plug comprising: a resilient rubber main body having a constant cross-section from end to end thereof and having two spaced contact prong recesses extending the entire axial length thereof and an intermediate recess adapted to receive the inner end of the electric cord, two metal contact prongs having barbed portions thereon inserted snugly into said spaced recesses, means for attaching the wires of said cord individually to said spaced contact prongs prior to slipping said prongs to their final position in said spaced recesses, said body having two relatively small axially extending slots interconnecting said cord recess to said prong recesses respectively thru which the attached wires may slide when said prongs and cord are slipped to their final position.

2. An electric push-in plug attached to the end of a flexible electric cord, said plug comprising: a resilient rubber main body of constant crosssection throughout its length and having two spaced contact prong recesses extending the entire axial length thereof and an intermediate recess adapted to receive the inner end of the electric cord, said cord-receiving recess communicating with both of said prong-receiving recesses by open-ended slots, two metal contact prongs having means on their inner ends for connecting same to the individual wires of said cord while said inner ends are uncovered by said rubber body, said cord and two prongs being slldable into final position in said rubber body after being connected together as a unit.

3. An electric push-in plug attached to the end of a flexible electric cord, said plug comprising: a resilient rubber main'body having a substantially centrally disposed through aperture snugly receiving the electric cord and two laterally adjacent through apertures snugly receiving the contact prongs, two elongated contact prongs having portions embedded in the resilient walls of said apertures, said cord-receiving aperture interconnecting with said two prong-receiving apertures by two open-ended wire-receiving narrow slots, whereby the individual wires of said cord may be individually connected to the inner ends of said two prongs prior to slipping said prongs with the wires connected thereto to their final position in said rubber body.

4. An electric push-in plug attached to the end of a flexible electric cord, said plug comprising: a resilient rubber main body having a constant cross-section and having a substantially central through aperture snugly receiving said cord and two laterally adjacent through apertures snugly receiving the contact prongs, two elongated contact prongs each having its inner end individually connected to one of the wires of said cord, said connections being thereafter forced to a con cealed location within the corresponding apertures, said cord-receiving aperture interconnecting with said two prong-receiving apertures by wire-receiving narrow slots whereby the individual wires of said cord may be connected to said prongs prior to inserting said prongs and cord to their final position in said rubber body.

HARVEY D. GEYER. 

